Looking for

- http://www.mangago.zone/read-manga/this_ending/
- http://www.mangago.zone/read-manga/the_timekeeper_s_final_summer/
- http://www.mangago.zone/read-manga/bokura_wa_nando_mo_koi_o_suru/
- http://www.mangago.zone/read-manga/don_t_provoke_reborn_ed_bamboo_horse/

Not really sure it's what you're looking for but there is time travel in the fourth

http://www.mangago.zone/read-manga/bokura_wa_nando_mo_koi_o_suru/
They didn't broke up but the other died

http://www.mangago.zone/read-manga/keeper_of_the_pearl/

It’s the this ending. Thank you very much! :3

ItMs not it but thank you!! :3